Quartz microprobes

Sample preparation is straightforward for a scattering process such as Raman spectroscopy. Sample containers can be of glass or quartz, which are weak Raman scatterers, and aqueous solutions pose no problems. Raman microprobes have a spatial resolution of - 1 //m, much better than the diffraction limit imposed on ir microscopes (213). Eiber-optic probes can be used in process monitoring (214). 

This investigation relied on petrographic analysis of polished sections using reflected light and the scanning electron microscopy (SEM) and electron microprobe (EPMA) analyses to identify minerals and to document the distribution of gold. The mineralized zone is coincident with a distinct bleached alteration zone that contains fine- to coarse-grained, subhedral arsenopyrite and pyrite in quartz-carbonate veins. 

Fig. 3.40 Histogram of 5 0-values of quartz in sandstone from 6-10 rm spots by ion microprobe. Mixed analyses are on the boundary of detrital quartz and quartz overgrowths (Kelly et al. 2007)...

Ellis AS, Johnson TM, Bullen TD (2004) Using chromium stable isotope ratios to quantify Cr(Vl) reduction lack of sorption effects. Environ Sci Techn 38 3604-3607 Elsenheimer D, VaUey JW (1992) In situ oxygen isotope analysis of feldspar and quartz by Nd-YAG laser microprobe. Chem Geol 101 21 2 EmUiani C (1955) Pleistocene temperatures. J Geol 63 538-578... 

In order to substantiate further the mineral matter content information received from the x-ray diffraction analyses, several coke pellets were scanned for sulfur, iron, calcium, silicon, aluminum and potassium in the electron microprobe. Electron probe results showed abundant silicon, suggesting quartz (Si02), considerable aluminum, suggesting kaolinite [Ali>Sii Oii(OH)4] and, relatively speaking, little iron, sulfur, calcium, or potassium. 

In order to overcome these problems, interest was focussed on that portion of the organic matter trapped in mineral precipitates which formed synchronously with sedimentation. In these cases, the material is hermetically sealed in the crystalline matter and may survive with relatively little subsequent alteration. Such preservation is common in cherts which are chemical precipitates of silica and now comist of fine grained quartz. These rocks offer the best chance for successful preservation of truely Precambrian molecular fossils. Modem microprobes and spectrophotometer microscopes allow the non-destructive analysis of organic matter enclosed in mineral crystals. Laser bombardment of microscopic... 

The NO concentration profiles are shown in Fig. 1 for both cooled and uncooled quartz microprobes and include measurements of N0X obtained using a Mo catalytic converter. 

IneflBdent quenching from incorrect fabrication of the quartz microprobes, resulting in continuation of chemical reaction along the sampling line. Properly designed probes may be 98% eflBcient. 

The diffusion flames of methanol [27], ethanol [27], n- and iso-propanol [27], and the four isomeric butanols [28] have been investigated using a quartz probe technique. The alcohol flames were burned on a pyrex wool wick and samples for analysis were taken from various positions in the flame using a quartz microprobe. Thermocouple measurements showed that the temperature varied from 200 °C at the wick to around 1400 °C at the tip and edges of the flame. 

Valley J. W. and Graham C. M. (1996) Ion microprobe analysis of oxygen isotope ratios in quartz from Skye granite healed micro-cracks, fluid flow, and hydrothermal exchange. Contrib. Mineral. Petrol. 124, 225-234. 

Figure 7. Grayscale wavelength-dispersive electron microprobe map of oxygen distribution showing iron oxyhydroxide rim (bright band) on quartz, in till sample LHP 8 from oxidized zone, Huron County, MI. Arsenic contents of points shown are as follows I 1,200 ppm 2 1,300 ppm 3 3,300 ppm 4 1,400 ppm 5 2,800 ppm 6 1,000 ppm. The maximum As concentration determined for this sample is 7,300ppm. Map area is 500 x 500 0.5 pm pixels.

Rock carvings made historically may have used steel. The presence of steel remains embedded in a carving would invalidate claims of antiquity, whereas presence of such material as quartz would be consistent with prehistoric age (Whitley et al., 1999). Meticulous sampling and examination of cross-section with electron microprobe is required to determine if steel remains exist in a petroglyph groove... 

The single crystal of gas hydrate prepared from H2 + CO2 and H2 + CO2 + THF mixtures was analyzed by in situ Raman spectroscopy using a laser Raman microprobe spectrophotometer with multichannel CCD detector. In the present study, the single crystal was defined as the gas hydrate crystal for which the Raman peak of the intermolecular 0-0 vibration mode can be detected. The argon ion laser beam (wavelength 514.5 nm, power 100 mW) or He-Ne laser beam (wavelength 632.8 nm, power 35 mW) condensed to 2 pm in spot diameter was irradiated to the sample through the upper sapphire (or quartz) window. The backscatter of the opposite direction was taken in with the same lens. The spectral resolution was about 1 cm ... 

Bohlke JK, Irwin JJ (1992a) Laser microprobe analyses of noble gas isotopes and halogens in fluid inclusions Analyses of microstandards and synthetic inclusions in quartz. Geochim Cosmochim Acta 56 187-201... 

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